No where near enough information to even start a DR design. No idea of databases, interdependencies, application servers, network setup, etc, etc.

0 data loss?  That's not going to come cheap. You need redundant network connections between the data centers, high speed networks, synchronous 'DR' of some form, log backups that go offsite immediately, etc. It's not easy at that point.
You need to look at other business restrictions, skills available in the admin team, budgets, and a lot of other things.

If they need 0 data loss in the case of a disaster, any disaster, then they probably should get in a top-level specialist to help them get the right setup. I recommend Denny Cherry. He's not cheap, but their requirement is not going to be cheap and with DR the cost of getting it wrong is often the largest cost.